Meadow producers capture 20,000 kJ/m²/year. Using the ten percent rule, about how much energy reaches primary consumers?

Phytoplankton contain 7,000 kJ/m² of energy. About how much is available to zooplankton that eat them?

An oak forest's producers store 36,000 kJ/m²/year. Approximately how much energy reaches caterpillars, the primary consumers?

In a pond, primary consumers contain 2,400 kJ/m². About how much energy can support secondary consumers?

A grasshopper population has 900 kJ/m² available to it. If frogs eat the grasshoppers, about how much energy reaches the frogs?

A lake's algae capture 12,000 kJ/m²/year. What energy amount is expected in herbivorous aquatic insects?

Shrubs in a desert food chain provide 4,500 kJ/m²/year. How much energy is transferred to rabbits that eat the shrubs?

A lizard population contains 300 kJ/m² of energy. A hawk eats the lizards. About how much energy becomes available to the hawk?

Use the bar graph's producer energy. Applying the ten percent rule, about how much energy should reach primary consumers?

Use the bar graph's primary-consumer energy. About how much energy is expected in secondary consumers?

Only about a tenth of energy at one trophic level reaches the next. Where does most of the remaining energy go?

A rabbit uses food energy to maintain body temperature, move, and breathe. Why does this reduce energy available to a fox?

A deer eats only part of the leaves produced in a forest. What happens to energy remaining in uneaten leaves?

An herbivore cannot digest all of the plant material it consumes. Why does this limit energy transfer to its predators?

Why is energy transfer between trophic levels less than 100% even when a predator eats all of its prey?

A student says that energy not transferred to the next trophic level has been destroyed. What correction is accurate?

Why do ectothermic animals often use less food energy for thermoregulation than birds or mammals?

Heat released by respiration at each trophic level cannot be used by producers to make food. What does this mean for energy in an ecosystem?

Use the energy pyramid. Moving from producers to primary consumers, by roughly what factor does energy decrease?

Use the bar graph. About how much biomass do the primary consumers contain?

Use the energy pyramid. Which trophic level contains approximately 90 kJ/m²/year?

Use the energy pyramid. About how much energy is available to tertiary consumers?

Use the biomass pyramid. Which comparison is supported by the data?

Use the energy pyramid. Which trophic level has the least energy available?

Why do food chains rarely extend beyond four or five trophic levels?

A farmer feeds corn to cattle, then people eat the beef. Compared with people eating the corn directly, what does the ten percent rule predict?

Why can a grassland support many more grasshoppers than hawks?

An apex predator is extirpated from a small reserve. Why had the reserve supported relatively few individuals of that predator even before the loss?

A lake becomes less productive after nutrient inputs are reduced. Which population is likely to decline first because of reduced energy at the base of the food web?

A wildlife manager compares two habitats with equal producer productivity. Habitat A has three trophic levels, while Habitat B has five. Which habitat can support more energy at its top consumer level?